I will assume that the steel, plastic, rubber and other materials for both the Hummer and Prius come from the same or similar sources. And so no major difference in the environmental impact of these materials.

3744 extra pounds of materials is 21 times the weight of a 176 pound battery pack. And the battery pack actually includes a lot of non lithium parts such as a frame, plastic holders, etc. So, the weight of the lithium itself is actually lower.

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Gasoline, and CO2 Impact:

Assume 200K miles over the lifetime of both vehicles.

Hummer: 9 to 10 MPG

Prius: 48 to 51 MPG

The Hummer gets about 5 times worse mileage than the Prius! But I guess everyone knew that.

Gasoline required for 200K miles:

Hummer: 200K/10 mpg = 20,000 gallons

Prius:200K/50 mpg = 4,000 gallons

Difference:The Hummer will consume 16,000 more gallons of gas over 200K miles. At $4 per gallon, that will cost an additional $64,000 over the life of the vehicle.

CO2 Over 200K Miles:

Assuming 19 pounds of CO2 per gallon

Hummer: 20,000 gallons * 19 pounds

= 380,000 pounds

= 190 tons of CO2

Prius: 4,000 * 19 pounds

= 76,000 pounds

= 38 tons of CO2

Difference:

The Hummer will create 152 more tons of CO2 over the life of the vehicle!

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So, the criticizers say that because of some pollution created by the lithium ion battery, the Hummer is better for the environment than a Prius, over the life of the vehicle.

If that is the case, the mining and production of the 176 pound battery pack (0.088 ton) lithium ion battery that costs $4000 would require the equivalent of the additional resources of at least:

3744 more pounds (1.872 tons) of steel, plastic, rubber, and other materials used in the production of the vehicles.

3 comments:

Excellent material Roger. I have a 2004 and love it. My previous vehicle got 24mpg and I now get 48mpg. It's saved me $4,000 in fuel in less than four years and is on track to be a free car in less than six years (bought it used for $10k).

They are planning to use lithium in future models of the Prius but haven't last I checked. All Nimh so far.Also, regarding the replacement cost of the NiMH batteries, there is a $1,500 or so core trade in value, so replacement should be more like $2,500 or even less. See:http://www.greencarreports.com/news/1078138_toyota-hybrid-battery-replacement-cost-guide

There are many positive effects of the use of a hybrid vehicle on the environment, and this is one of the main reasons why many people chose to buy hybrid cars that run on conventional gas. Prius Hybrid Battery